The Californium-252 plasma desorption mass spectrometer puts unusual and stringent demands on the data system that controls the spectrometer and acquires and processes its data output. Real-time performance and the ability to access very large data arrays in main memory are key considerations. CSL evaluated alternatives to meet the data processing needs of the instrument and recommended a more recent model of the computer used for this purpose at Texas A&M University. This data system has been purchased and will be operational soon. Special interface electronics and stepping motor controllers for automatic tuning are under construction in CSL.